=Paper= {{Paper |id=Vol-1178/CLEF2012wn-ImageCLEF-MullerEt2012 |storemode=property |title=Overview of the ImageCLEF 2012 Medical Image Retrieval and Classification Tasks |pdfUrl=https://ceur-ws.org/Vol-1178/CLEF2012wn-ImageCLEF-MullerEt2012.pdf |volume=Vol-1178 |dblpUrl=https://dblp.org/rec/conf/clef/MullerHKDAE12 }} ==Overview of the ImageCLEF 2012 Medical Image Retrieval and Classification Tasks== https://ceur-ws.org/Vol-1178/CLEF2012wn-ImageCLEF-MullerEt2012.pdf
Overview of the ImageCLEF 2012 medical image
        retrieval and classification tasks

 Henning Müller1,2 , Alba G. Seco de Herrera 1 , Jayashree Kalpathy–Cramer3 ,
          Dina Demner Fushman4 , Sameer Antani4 , Ivan Eggel 1
       1
           University of Applied Sciences Western Switzerland, Sierre, Switzerland
                  2
                    Medical Informatics, University of Geneva, Switzerland
                         3
                           Harvard University, Cambridge, MA, USA
                         4
                           National Library of Medicine (NLM), USA
                                  henning.mueller@hevs.ch


       Abstract. The ninth edition of the ImageCLEF medical image retrieval
       and classification tasks was organized in 2012. A subset of the open access
       collection of PubMed Central was used as the database in 2012, using
       a larger number of over 300’000 images than in 2011. As in previous
       years, there were three subtasks: modality classification, image–based
       and case–based retrieval.
       A new hierarchy for article figures was created for the modality classifi-
       cation task. The modality detection could be one of the most important
       filters to limit the search and focus the results sets. The goal of the
       image–based and the case–based retrieval tasks were similar compared
       to 2011 adding mainly complexity.
       The number of groups submitting runs has remained stable at 17, with
       the number of submitted runs remaining roughly the same with 202
       (207 in 2011). Of these, 122 were image–based retrieval runs, 37 were
       case–based runs while the remaining 43 were modality classification runs.
       Depending on the exact nature of the task, visual, textual or multimodal
       approaches performed better.


1     Introduction
The CLEF 20121 labs continue the CLEF tradition of community–based bench-
marking and complement it with workshops on emerging topics on information
retrieval evaluation methodologies. Following the format introduced in 2010, two
forms of labs were offered: labs could either be run as benchmarking activities
campaign–style during the ten month period preceding the conference, or as
workshop–style labs that explore possible benchmarking activities and provide
a means to discuss information retrieval evaluation challenges from various per-
spectives.
    ImageCLEF2 [1–4] is part of CLEF and focuses on cross–language and language–
independent annotation and retrieval of images. ImageCLEF has been organized
since 2003. Four tasks were offered in 2012:
1
    http://www.clef2012.org/
2
    http://www.imageclef.org/
 – medical image classification and retrieval;
 – photo annotation and retrieval (large–scale web, Flickr, and personal photo
   tasks);
 – plant identification;
 – robot vision.
The medical image classification and retrieval task in 2012 is a use case of the
PROMISE3 network of excellence and is supported by the project. This task
covers image modality classification and image retrieval with visual, semantic
and mixed topics in several languages using a data collection from the biomed-
ical literature. This year, there are three types of tasks in the medical image
classification and retrieval task:
 – modality classification;
 – image–based retrieval;
 – case–based retrieval.
This article presents the main results of the tasks and compares results between
the various participating groups and the techniques employed.


2     Participation, Data Sets, Tasks, Ground Truth
This section describes the details concerning the set–up and the participation in
the medical retrieval task in 2012.

2.1    Participation
In total over 60 groups registered for the medical tasks and obtained access to
the data sets. ImageCLEF in total had over 200 registrations in 2012, with a
bit more than 30% of the groups submitting results. 17 of the registered groups
submitted results to the medical tasks, the same number as in previous years.
The following groups submitted at least one run:
 – Bioingenium (National University of Colombia, Colombia)*;
 – BUAA AUDR (BeiHang University, Beijing, China);
 – DEMIR (Dokuz Eylul University, Turkey);
 – ETFBL (Faculty of Electrical Engineering Banja Luka, Bosnia and Herze-
   govina)*;
 – FINKI (University in Skopje, Macedonia)*;
 – GEIAL (General Electric Industrial Automation Limited, United States)*;
 – IBM Multimedia Analytics (United States)*;
 – IPL (Athens University of Economics and Business, Greece);
 – ITI (Image and Text Integration Project, NLM, United States)*;
 – LABERINTO (Universidad de Huelva, Spain);
 – lambdasfsu (San Francisco State University, United States)*;
3
    http://www.promise-noe.eu/
 – medGIFT (University of Applied Sciences Western Switzerland, Switzer-
   land);
 – MIRACL (Higher Institute of Computer Science and Multimedia of Sfax,
   Tunisia)*;
 – MRIM (Laboratoire d’Informatique de Grenoble, France);
 – ReDCAD (National School of Engineering of Sfax, Tunisia)*;
 – UESTC (University of Electronic Science and Technology, China);
 – UNED–UV (Universidad Nacional de Educacion a Distancia and Universitat
   de València, Spain);
Participants marked with a star had not participated in the medical retrieval
task in 2011.
   A total of 202 valid runs were submitted, 43 of which were submitted for
modality detection, 122 for the image–based topics and 37 for the case–based
topics. The number of runs per group was limited to ten per subtask and case–
based and image–based topics were seen as separate subtasks in this view.

2.2    Datasets
In ImageCLEFmed 2012, a larger database than 2011 was provided using the
same types of images and the same journals. The database contains over 300,000
images of 75’000 articles of the biomedical open access literature that allow free
redistribution of the data. The ImageCLEF database is a subset of the PubMed
Central4 database containing in total over 1.5 million images. PubMedCentral
contains all articles in PubMed that are open access but the exact copyright for
redistribution varies among the journals.

2.3    Modality Classification
Previous studies [5, 6] have shown that imaging modality is an important infor-
mation on the image for medical retrieval. In user–studies [7], clinicians have
indicated that modality is one of the most important filters that they would like
to be able to limit their search by. Many image retrieval websites (Goldminer,
Yottalook) allow users to limit the search results to a particular modality [8].
Using the modality information, the retrieval results can often be improved sig-
nificantly [9].
   An improved ad–hoc hierarchy with 31 classes in the sections compound or
multipane images, diagnostic images and generic biomedical illustrations was
created based on the existing data set [10]. The following hierarchy was used for
the modality classification, more complex than the classes in ImageCLEF 2011.
   The class codes with descriptions are the following ([Class code] Description):
 – [COM P ] Compound or multipane images (1 category)
 – [Dxxx] Diagnostic images:
     • [DRxx] Radiology (7 categories):
4
    http://www.ncbi.nlm.nih.gov/pmc/
Fig. 1. The image classes hierarchy that was development for document images occur-
ring in the biomedical open access literature.


     • [DRU S] Ultrasound
     • [DRM R] Magnetic Resonance
     • [DRCT ] Computerized Tomography
     • [DRXR] X–Ray, 2D Radiography
     • [DRAN ] Angiography
     • [DRP E] PET
     • [DRCO] Combined modalities in one image
 – [DV xx] Visible light photography (3 categories):
     • [DV DM ] Dermatology, skin
     • [DV EN ] Endoscopy
     • [DV OR] Other organs
 – [DSxx] Printed signals, waves (3 categories):
     • [DSEE] Electroencephalography
     • [DSEC] Electrocardiography
     • [DSEM ] Electromyography
 – [DM xx] Microscopy (4 categories):
     • [DM LI] Light microscopy
     • [DM EL] Electron microscopy
     • [DM T R] Transmission microscopy
     • [DM F L] Fluorescence microscopy
 – [D3DR] 3D reconstructions (1 category)
 – [Gxxx] Generic biomedical illustrations (12 categories):
     • [GT AB] Tables and forms
      • [GP LI] Program listing
      • [GF IG] Statistical figures, graphs, charts
      • [GSCR] Screenshots
      • [GF LO] Flowcharts
      • [GSY S] System overviews
      • [GGEN ] Gene sequence
      • [GGEL] Chromatography, Gel
      • [GCHE] Chemical structure
      • [GM AT ] Mathematics, formulae
      • [GN CP ] Non–clinical photos
      • [GHDR] Hand–drawn sketches

For this hierarchy 1,000 training images and 1,000 test images were provided to
the participants. Labels for the training images were known whereas labels for
the test images were distributed after the results submission, only.


2.4   Image–Based Topics

The image–based retrieval task is the classic medical retrieval task, similar to
the tasks organized from 2004 to 2011 where the query targets are single images.
Participants were given a set of 22 textual queries (in English, Spanish, French
and German) with 1–7 sample images for each query. The queries were classified
into textual, mixed and semantic queries, based on the methods that are expected
to yield the best results.
    The topics for the image–based retrieval task were based on a selection of
queries from search logs of the Goldminer radiology image search system [11].
Only queries occurring 10 times or more (about 200 queries) were considered
as candidate topics for this task. A radiologist assessed the importance of the
candidate topics, resulting in 50 candidate topics that were checked for at least
occurring a few times in the database. The resulting 22 queries were then dis-
tributed among the participants and example query images were selected from
a past collection of ImageCLEF [12].


2.5   Case–Based Topics

The case–based retrieval task was first introduced in 2009. This is a more com-
plex task but one that we believe is closer to the clinical workflow. In this task, 30
case descriptions with patient demographics, limited symptoms and test results
including imaging studies were provided (but not the final diagnosis). The goal
was to retrieve cases including images that a physician would judge as relevant
for differential diagnosis. Unlike the ad–hoc task, the unit of retrieval here was
a case, not an image. The topics were created form an existing medical case
database. Topics included a narrative text and several images.
2.6   Relevance Judgements
The relevance judgements were performed with the same on–line system as in
2008–2011 for the image–based topics as well as case–based topics. For the case–
based topics, the system displays the article title and several images appearing in
the text (currently the first six, but this can be configured). Judges were provided
with a protocol for the process with specific details on what should be regarded
as relevant versus non–relevant. A ternary judgement scheme was used again,
wherein each image in each pool was judged to be “relevant”, “partly relevant”,
or “non–relevant”. Images clearly corresponding to all criteria were judged as
“relevant”, images for which relevance could not be accurately confirmed were
marked as “partly relevant” and images for which one or more criteria of the
topic were not met were marked as “non–relevant”. Judges were instructed in
these criteria and results were manually verified during the judgement process.
As in previous years, judges were recruited by sending out an email to current and
former students at OHSU’s (Oregon Health and Science University) Department
of Medical Informatics and Clinical Epidemiology. Judges, primarily clinicians,
were paid a small stipend for their services. Many topics were judged by two or
more judges to explore inter–rater agreements and its effects on the robustness
of the rankings of the systems.


3     Results
This section describes the results of ImageCLEF 2012. Runs are ordered based
on the tasks (modality classification, image–based and case–based retrieval) and
the techniques used (visual, textual, mixed).
   17 teams submitted at least one run in 2012, the same number than in 2011.

3.1   Modality Classification Results
The results of the modality classification task are compared using classification
accuracy. With a higher number of classes, this task was more complex than in
previous years. As seen in Table 1, the best result were obtained by the IBM
Multimedia Analytics [13] group using visual methods (69.6%). In previous years
combining visual and textual methods most often provided the best results. The
best run using visual methods had a slightly better accuracy than the best
run using mixed methods (66.2%) by the medGIFT group [14]. Only a single
group submitted text–based results that performed worse than the average of all
runs. The best run using textual methods alone obtained a much lower accuracy
(41.3%).

Techniques Used for Visual Classification The IBM Multimedia Analytics
team used multiple features extracted from a set of image granularities with
Kernel approximation fusion in the best run [13]. A variety of image process-
ing techniques were explored by the other participants. Multiple features were
            Table 1. Results of the runs of modality classification task.


Run                                                     Group                    Run Type Accuracy
medgift–nb–mixed–reci–14–mc                             medGIFT                   Mixed     66,2
medgift–orig–mixed–reci–7–mc                            medGIFT                   Mixed     64,6
medgift–nb–mixed–reci–7–mc                              medGIFT                   Mixed     63,6
Visual Text Hierarchy w Postprocessing 4 Illustration   ITI                       Mixed     63,2
Visual Text Flat w Postprocessing 4 Illustration        ITI                       Mixed     61,7
Visual Text Hierarchy                                   ITI                       Mixed     60,1
Visual Text Flat                                        ITI                       Mixed     59,1
medgift–b–mixed–reci–7–mc                               medGIFT                   Mixed     58,8
Image Text Hierarchy Entire set                         ITI                       Mixed     44,2
IPL MODALITY SVM LSA BHIST 324segs 50k WithTextV        IPL                       Mixed     23,8
Text only Hierarchy                                     ITI                       Textual   41,3
Text only Flat                                          ITI                       Textual   39,4
preds Mic Combo100Early MAX extended100                 IBM Multimedia Analytics Visual     69,6
LL fusion nfea 20 rescale                               IBM Multimedia Analytics Visual     61,8
preds Mic comboEarly regular                            IBM Multimedia Analytics Visual     57,9
UESTC–MKL3                                              UESTC                     Visual    57,8
UESTC–MKL2                                              UESTC                     Visual    56,6
UESTC–MKL5                                              UESTC                     Visual    55,9
UESTC–MKL6                                              UESTC                     Visual    55,9
NCFC ORIG 2 EXTERNAL SUBMIT                             IBM Multimedia Analytics Visual     52,7
UESTC–SIFT                                              UESTC                     Visual    52,7
Visual only Hierarchy                                   ITI                       Visual    51,6
Visual only Flat                                        ITI                       Visual    50,3
gist84 01 ETFBL                                         ETFBL                     Visual    48,5
gist84 02 ETFBL                                         ETFBL                     Visual    47,9
LL 2 EXTERNAL                                           IBM Multimedia Analytics Visual     46,5
medgift–nb–visual–mnz–14–mc                             medGIFT                   Visual    42,2
medgift–nb–visual–mnz–7–mc                              medGIFT                   Visual    41,8
modality visualonly                                     GEIAL                     Visual    39,5
medgift–orig–visual–mnz–7–mc                            medGIFT                   Visual    38,1
medgift–b–visual–mnz–7–mc                               medGIFT                   Visual    34,2
NCFC 500 2 EXTERNAL SUBMIT                              IBM Multimedia Analytics Visual     33,4
preds Mic comboLate MAX regular                         IBM Multimedia Analytics Visual     27,5
IPL AllFigs MODALITY SVM LSA BHIST 324segs 50k          IPL                       Visual    26,6
IPL MODALITY SVM LSA BHIST 324segs 50k                  IPL                       Visual    26,4
preds Mic comboLate MAX extended100                     IBM Multimedia Analytics   Visua    22,1
UNED UV 04 CLASS IMG ADAPTATIVEADJUST                   UNED–UV                   Visual    15,7
UNED UV 03 CLASS IMG ADJUST2MINRELEVANTS                UNED–UV                   Visual    13,4
UNED UV 02 CLASS IMG ADJUST2AVGRELEVANTS                UNED–UV                   Visual    13,1
UNED UV 01 CLASS IMG NOTADJUST                          UNED–UV                   Visual    11,9
baseline–sift–k11–mc                                    medGIFT                   Visual    11,1
testimagelabelres                                       GEIAL                     Visual    10,1
ModalityClassificaiotnSubmit                             BUAA AUDR                 Manual     3,0
extracted from the images, most frequently scale–invariant feature transform
(SIFT) variants [13–17], GIST (gist is not an acronym) [13], local binary pat-
terns (LBP) [13, 17], edge and color histograms [13, 16–19] and gray value his-
tograms [16]. Several texture features were also explored such us Tamura [13,
16–18], Gabor filters [16–18], Curvelets [13], a granulometric distribution func-
tion [19] and spatial size distribution [19]. For recognizing compound images
ITI used an algorithm that detects sub–figure labels and the border of each
sub–figure within a compound image [17].
    k–Nearest Neighbors (kNN) [14], a logistic regression model [19] or multi–
class support vector machines (SVMs) [13, 16–18] were employed to classify the
images into the 32 categories. Only one group used hierarchical classification [17].
    Three groups augmented the training data with additional examples for the
categories [13, 14, 18]. Not all details of the training data expansion are clear and
it needs to be assured that purely visual runs such as the best–performing run
only use visual features for the training data set expansion.

Techniques Used for Classification Based on Text ITI [17] was the only
group submitting a run for the textual modality classification task. They ex-
tracted the unified medical language system (UMLS) synonyms using the Essie
system [20] and used it for term expansion when indexing enriched citations with
Lucene/SOLR5 .

Techniques Used for Multimodal Classification Three groups submitted
multimodal runs for the classification task. The medGIFT team obtained the
best results [14] (66.2%). The approach fuses Bag–of–Visual–Words (BoVW)
features based on SIFT and Bag–of–Colors (BoC) representing local image colors
using reciprocal rank fusion. All three groups used techniques based on the
Lucene search engine for the textual part and simple fusion techniques.

3.2    Image–Based Retrieval Results
13 teams submitted 36 visual, 54 textual and 32 mixed runs for the image–
based retrieval task. The best result in terms of mean average precision (MAP)
was obtained by ITI [17] using multimodal methods. The second best run was
a purely textual run submitted by Bioingenium [21]. As in previous years, vi-
sual approaches achieved much lower results than the textual and multimodal
techniques.

Visual Retrieval 36 of the 122 submitted runs used purely visual techniques.
As seen in Table 2, DEMIR [22] achieved the best MAP, 0.0101, performing
explicit grade relevance feedback. The second best run (M AP = 0.0092) was
achieved also by DEMIR without applying relevance feedback. They combined
color and edge directivity (CEDD) using combSUM [17, 21–23]. Bioingenium [21]
5
    http://lucene.apache.org/
submitted the third best run (M AP = 0.0073). They used a spatial pyramid
extension for the CEDD.
    In addition to the techniques used in the modality classification task, par-
ticipants used visual features such as visual MPEG–7 features [22, 24], scal-
able color [24] and brightness/texture directionality histograms (BTDH) [22,
23]. Other techniques used are fuzzy color and texture histograms (FCTH) [17,
22, 23] and color layout (CL) [22, 24]. To extract these features most partici-
pants used tools such as Rummager [22, 23] or LIRE (Lucene Image Retrieval
Engine) [24].


     Table 2. Results of the visual runs for the medical image retrieval task.


Run Name                                        Group       MAP GM-MAP bpref P10         P30
RFBr23+91qsum(CEDD,FCTH,CLD)max2012             DEMIR       0,0101 0,0004 0,0193 0,0591 0,0439
IntgeretedCombsum(CEDD,FCTH,CLD)max             DEMIR       0,0092 0,0005  0,019 0,05 0,0424
unal                                            Bioingenium 0,0073 0,0003 0,0134 0,0636 0,05
FOmixedsum(CEDD,FCTH,CLD)max2012                DEMIR       0,0066 0,0003 0,0141 0,0318 0,0288
edCEDD&FCTH&CLDmax2012                          DEMIR       0,0064 0,0003 0,0154 0,0409 0,0318
medgift-lf-boc-bovw-mnz-ib                      medGIFT     0,0049 0,0003 0,0138 0,0364 0,0364
Combined LateFusion Fileterd Merge              ITI         0,0046 0,0003 0,0107 0,0318 0,0379
FilterOutEDFCTHsum2012                          DEMIR       0,0042 0,0004 0,0109 0,0409 0,0364
finki                                            FINKI       0,0041 0,0003 0,0105 0,0318 0,0364
EDCEDDSUMmed2012                                DEMIR        0,004 0,0003 0,0091 0,0364 0,0409
medgift-lf-boc-bovw-reci-ib                     medGIFT      0,004 0,0002 0,0103 0,0227 0,0318
edFCTHsum2012                                   DEMIR       0,0034 0,0003  0,01 0,0318 0,0318
medgift-ef-boc-bovw-mnz-ib                      medGIFT     0,0033 0,0003 0,0133 0,0364 0,0333
UNAL                                            Bioingenium 0,0033 0,0003 0,011 0,0455 0,0364
EDCEDD&FCTHmax2012                              DEMIR       0,0032 0,0003 0,0111 0,0227 0,0303
medgift-ef-boc-bovw-reci-ib                     medGIFT      0,003 0,0001  0,01 0,0273 0,0227
IntgeretedCombsum(CEDD,FCTH)max                 DEMIR       0,0027 0,0003 0,0099 0,0045 0,0212
edMPEG7CLDsum2012                               DEMIR       0,0026 0,0002 0,0058 0,0318 0,0242
UNAL                                            Bioingenium 0,0024 0,0001 0,0113 0,0091 0,0045
medgift-lf-boc-bovw-mnz-ib                      medGIFT     0,0022 0,0001 0,0062 0,0227 0,0318
IPL AUEB DataFusion LSA SC CL CSH 64seg 20k     IPL         0,0021 0,0001 0,0049 0,0273 0,0242
IPL AUEB DataFusion EH LSA SC CL CSH 64seg 100k IPL         0,0018 0,0001 0,0053 0,0364 0,0258
IPL AUEB DataFusion EH LSA SC CL CSH 64seg 20k IPl          0,0017 0,0001 0,0053 0,0227 0,0273
IPL AUEB DataFusion LSA SC CL CSH 64seg 100k    IPL         0,0017 0,0002 0,0046 0,0364 0,0212
baseline-sift-early-fusion-ib                   medGIFT     0,0017    0   0,0058 0,0227 0,0318
baseline-sift-late-fusion                       medGIFT     0,0016    0   0,0048 0,0273 0,0318
IPL AUEB DataFusion EH LSA SC CL CSH 64seg 50k IPL          0,0011 0,0001  0,004 0,0136 0,0136
IPL AUEB DataFusion LSA SC CL CSH 64seg 50k     IPL         0,0011 0,0001 0,0039 0,0091 0,0121
Combined Selected Fileterd Merge                ITI         0,0009    0   0,0028 0,0227 0,0258
reg cityblock                                   lambdasfsu 0,0007     0   0,0024 0,0227 0,0197
reg diffusion                                    lambdasfsu 0,0007     0   0,0023 0,0182 0,0182
tfidf of pca euclidean                           lambdasfsu 0,0005     0   0,0011 0,0136 0,0136
tfidf of pca cosine                              lambdasfsu 0,0005     0   0,0013 0,0091 0,0167
tfidf of pca correlation                         lambdasfsu 0,0005     0   0,0011 0,0136 0,0167
itml cityblock                                  lambdasfsu 0,0001     0   0,0014 0,0045 0,003
itml diffusion                                   lambdasfsu 0,0001     0   0,0015 0,0045 0,003




Textual Retrieval Table 3 shows that the Bioingenium [21] team achieved the
best MAP using textual techniques (0.2182). They developed their own imple-
mentation of Okapi–BM25. The BUAA AUDR [18] team achieved the second
best textual result (0.2081) with a run indexed with MeSH for query expansion
and modality prediction. The remaining participants explored a variety of re-
trieval techniques such as stop word and special character removal, tokenization
and stemming (e. g. Porter stemmer) [19, 22–25]. For text indexing many groups
used Terrier [22, 23, 26, 27]. In 2012, some groups included concept features [16,
25, 26] using tools such as MetaMap or MeSHUP. Query expansion [22, 28] was
also explored.


Multimodal Retrieval The run with the highest MAP in the image retrieval
task was a multimodal run submitted by the ITI team [17] (0.2377), see also Ta-
ble 4. For this run various low–level visual descriptors were extracted to create
the BoVW. This BoVW was combined with words taken from the topic descrip-
tion to form a multimodal query appropriate for Essie. ITI also submitted the
second best mixed run (M AP = 0.2166) that has a slightly worse MAP than
the best textual run (M AP = 0.2182).
    Several late fusion strategies were used by the participants such as the prod-
uct fusion algorithm [19], a linear weighed fusion strategy [23], reciprocal rank
fusion [14], weighted combSUM [22] and combMNZ [14].


3.3    Case–based Retrieval Results

In 2012, 37 runs were submitted in the case–based retrieval task. As in previous
years most of them were textual runs. Only the medGIFT team [14] submitted
visual and multimodal case–based retrieval runs. Although textual runs achieved
the best results, a mixed approach performs better than the average of all sub-
mitted runs in this task. Visual runs do not perform as well as most of the
textual retrieval runs.


Visual Retrieval Table 5 shows the results using visual retrieval on the case–
based task. The medGIFT team [14] is the only group that submitted a multi-
modal run in this task, using a combination of BoVW and BoC and obtaining
the best accuracy in the multimodal classification task. The results also show
that there can be an enormous difference combining the two base feature sets.


Textual Retrieval The medGIFT team [14] achieved the highest MAP, 0.169,
among all submitted runs. For this run only the standard Lucene baseline was
used. The second best run was submitted by MRIM (M AP = 0.1508) [28].
MRIM proposed a solution to the frequency shift thrugh a new counting strategy.
    In addition to the techniques used in other tasks, the participants used seman-
tic similarity [13, 16] measures. Moreover, three of the six groups participating
used concept–based approaches [16, 25, 28]. The ITI team [17] used the Google
Search API6 to determine relevant disease names to correspond to signs and
symptoms found in a topic case.
6
    https://developers.google.com/custom-search/v1/overview
    Table 3. Results of the textual runs for the medical image retrieval task.


Run Name                                   Group       MAP GM-MAP bpref P10         P30
UNAL                                       Bioingenium 0.2182  0.082 0.2173 0.3409 0.2045
AUDR TFIDF CAPTION[QE2] AND ARTICLE        BUAA AUDR 0.2081 0.0776 0.2134 0.3091 0.2045
AUDR TFIDF CAPTION[QE2] AND ARTICLE        BUAA AUDR 0.2016 0.0601 0.2049 0.3045 0.1939
IPL A1T113C335M1                           IPL         0.2001 0.0752 0.1944 0.2955 0.2091
IPL A10T10C60M2                            IPL         0.1999 0.0714 0.1954 0.3136 0.2076
TF IDF                                     DEMIR       0.1905 0.0531 0.1822 0.3318 0.2152
AUDR TFIDF CAPTION AND ARTICLE             BUAA AUDR 0.1891 0.0508 0.1975 0.3318 0.1939
IPL T10C60M2                               IPL          0.188 0.0694 0.1957 0.3364 0.2076
AUDR TFIDF CAPTION[QE2]                    BUAA AUDR 0.1877 0.0519 0.1997 0.3 0.2045
TF IDF                                     DEMIR       0.1865 0.0502 0.1981 0.25 0.1515
Laberinto MSH PESO 2                       Laberinto   0.1859 0.0537 0.1939 0.3318 0.1894
IPL TCM                                    IPL         0.1853 0.0755 0.1832 0.3091 0.2152
IPL T113C335M1                             IPl         0.1836 0.0706 0.1868 0.3318 0.2061
UNAL                                       Bioingenium 0.1832 0.0464 0.1822 0.2955 0.1939
TF IDF                                     DEMIR       0.1819 0.0679 0.1921 0.2864 0.1909
TF IDF                                     DEMIR       0.1814 0.0693 0.1829 0.2864 0.1894
UESTC-ad-tc                                UESTC       0.1769 0.0614 0.1584 0.3 0.1621
finki                                       FINKI       0.1763 0.0498 0.1773 0.2909 0.1864
Laberinto MSH PESO 1                       Laberinto   0.1707 0.0512 0.1712 0.3318 0.1894
finki                                       FINKI       0.1704 0.0472 0.1701 0.3091 0.1833
Laberinto MMTx MSH PESO 2                  Laberinto   0.168  0.0555 0.1711 0.3227 0.1909
Terrier CapTitAbs BM25b0.75                ReDCAD      0.1678 0.0661 0.1782 0.2818 0.1712
Laberinto MMTx MSH PESO 1                  Laberinto   0.1677 0.0554 0.1701 0.3182 0.1879
AUDR TFIDF CAPTION[QE2]                    BUAA AUDR 0.1673    0.037 0.1696 0.2955 0.1894
Laberinto BL                               Laberinto   0.1658 0.0477 0.1667 0.3 0.1939
AUDR TFIDF CAPTION                         BUAA AUDR 0.1651 0.0467 0.1743 0.3 0.2076
AUDR TFIDF CAPTION                         BUAA AUDR 0.1648 0.0441 0.1717 0.3318 0.1909
finki                                       FINKI       0.1638 0.0444 0.1644 0.3 0.1818
IPL ATCM                                   IPL         0.1616 0.0615 0.1576 0.2773 0.1742
Laberinto BL MSH                           Laberinto   0.1613 0.0462 0.1812 0.2682 0.1864
LIG MRIM IB TFIDF W avdl DintQ             MRIM        0.1586 0.0465 0.1596 0.3455 0.2136
HES-SO-VS CAPTIONS LUCENE                  medGIFT     0.1562 0.0424  0.167 0.3273 0.1864
TF IDF                                     DEMIR       0.1447 0.0313 0.1445 0.2864 0.1742
UESTC-ad-c                                 UESTC       0.1443 0.0352 0.1446 0.2409 0.1485
UESTC-ad-tcm                               UESTC       0.1434  0.051 0.1397 0.2182 0.153
LIG MRIM IB FUSION TFIDF W TB C avdl DintQ MRIM        0.1432 0.0462 0.1412 0.2682 0.1955
LIG MRIM IB FUSION JM01 W TB C             MRIM        0.1425 0.0476 0.1526 0.2636 0.1924
HES-SO-VS FULLTEXT LUCENE                  medGIFT     0.1397 0.0436 0.1565 0.2227 0.1379
LIG MRIM IB TB PIVv2 C                     MRIM        0.1383 0.0405 0.1463 0.2864 0.1803
TF IDF                                     DEMIR       0.1372 0.0466 0.1683 0.3 0.1818
Laberinto MMTx MSH                         Laberinto   0.1361 0.0438  0.157 0.2091 0.1758
LIG MRIM IB TFIDF C avdl DintQ             MRIM        0.1345 0.0402 0.1304 0.2545 0.1682
LIG MRIM IB TB JM01 C                      MRIM        0.1342 0.0396  0.142 0.2818 0.1652
LIG MRIM IB TB BM25 C                      MRIM        0.1165  0.036 0.1276 0.2 0.1515
LIG MRIM IB TB TFIDF C avdl                MRIM        0.1081 0.0332 0.1052 0.1818 0.1167
UESTC-ad-cm                                UESTC        0.106 0.0206 0.1154 0.2091 0.1379
UESTC ad tcm mc                            UESTC        0.101 0.0132 0.1223 0.2 0.1333
LIG MRIM IB TB DIR C                       MRIM        0.0993 0.0281 0.1046 0.1864 0.1379
AUDR TFIDF CAPTION AND ARTICLE             BUAA AUDR 0.0959 0.0164 0.1075 0.1636 0.1152
LIG MRIM IB TB TFIDF C                     MRIM          0.09  0.026 0.0889 0.1409 0.1136
UESTC-ad-cm-mc                             UESTC       0.0653 0.0078 0.0846 0.1727 0.103
UNED UV 01 TXT AUTO EN                     UNED–UV     0.0039 0.0001 0.0055 0.0091 0.0076
UNAL                                       Bioingenium 0.0024 0.0001 0.0113 0.0091 0.0045
  Table 4. Results of the multimodal runs for the medical image retrieval task.


Run Name                                            Group   MAP GM-MAP bpref P10         P30
nlm-se                                              ITI     0.2377 0.0665 0.2542 0.3682 0.2712
Merge RankToScore weighted                          ITI     0.2166 0.0616 0.2198 0.3682 0.2409
mixedsum(CEDD,FCTH,CLD)+1.7TFIDFmax2012             DEMIR   0.2111 0.0645 0.2241 0.3636 0.2242
mixedFCTH+1.7TFIDFsum2012                           DEMIR   0.2085 0.0621 0.2204 0.3545 0.2152
medgift-ef-mixed-mnz-ib                             medGIFT 0.2005 0.0917 0.1947 0.3091 0.2
mixedCEDD+1.7TFIDFsum2012                           DEMIR   0.1954 0.0566 0.2096 0.3455 0.2182
nlm-lc                                              ITI     0.1941 0.0584 0.1871 0.2727 0.197
nlm-lc-cw-mf                                        ITI     0.1938 0.0413 0.1924 0.2636 0.2061
nlm-lc-scw-mf                                       ITI     0.1927 0.0395  0.194 0.2636 0.203
nlm-se-scw-mf                                       ITI     0.1914 0.0206 0.2062 0.2864 0.2076
Txt Img Wighted Merge                               ITI     0.1846 0.0538 0.2039 0.3091 0.2621
mixedsum(CEDD,FCTH,CLD)+TFIDFmax2012                DEMIR   0.1817 0.0574 0.1997 0.3409 0.2121
mixedFCTH+TFIDFsum2012                              DEMIR   0.1816 0.0527 0.1912 0.3409 0.2076
finki                                                FINKI   0.1794  0.049 0.1851 0.3 0.1894
finki                                                FINKI   0.1784 0.0487 0.1825 0.2955 0.1864
nlm-se-cw-mf                                        ITI     0.1774 0.0141 0.1868 0.2909 0.2091
mixedCEDD+textsum2012                               DEMIR   0.1682 0.0478 0.1825 0.3136 0.2061
FOmixedsum(CEDD,FCTH,CLD)+1.7TFIDFmax2012           DEMIR   0.1637 0.0349 0.1705 0.2773 0.1758
RFBr24+91qsum(CEDD,FCTH,CLD)+1.7TFIDFmax2012        DEMIR   0.1589 0.0424 0.1773 0.3136 0.1985
medgift-ef-mixed-reci-ib                            medGIFT 0.1167 0.0383 0.1238 0.1864 0.1485
UNED UV 04 TXTIMG AUTO LOWLEVEL FEAT...             UNED–UV 0.004  0.0001 0.0104 0.0409 0.0258
UNED UV 05 IMG EXPANDED FEATURES UNIQUE...          UNED–UV 0.0036 0.0001 0.0111 0.0455 0.0303
UNED UV 02 IMG AUTO LOWLEVEL FEATURES               UNED–UV 0.0034 0.0001 0.0114 0.0455 0.0273
UNED UV 08 IMG AUTO CONCEPTUAL FEATURES             UNED–UV 0.0033 0.0001 0.0104 0.0227 0.0197
IPL AUEB SVM CLASS LSA BlockHist324Seg 50k          IPL     0.0032 0.0002 0.0103 0.0409 0.0303
IPL AUEB SVM CLASS TEXT LSA BlockHist324Seg 50k     IPL     0.0025 0.0001 0.0095 0.0318 0.0258
IPL AUEB CLASS LSA BlockColorLayout64Seg 50k        IPL     0.0023 0.0002 0.0095 0.0318 0.0227
UNED UV 09 TXTIMG AUTO CONCEPTUAL FEAT...           UNED–UV 0.0021 0.0001  0.005 0.0091 0.0061
IPL AUEB CLASS LSA BlockColorLayout64Seg 20k        IPL     0.0019 0.0001 0.0066 0.0227 0.0197
UNED UV 03 TXTIMG AUTO LOWLEVEL FEAT...             UNED–UV 0.0015 0.0001 0.0037 0.0045 0.0061
UNED UV 07 TXTIMG AUTO EXPANDED FEAT...             UNED–UV 0.0015 0.0001 0.0036 0.0045 0.0061
UNED UV 06 TXTIMG AUTO EXPANDED FEAT...             UNED–UV 0.0013 0.0001 0.0034 0.0091 0.0045




   Table 5. Results of the visual runs for the medical case–based retrieval task.
    Run Name                           Group   MAP GM-MAP bpref P10         P30
    medgift-lf-boc-bovw-reci-IMAGES-cb medGIFT 0,0366 0,0014 0,0347 0,0269 0,0141
    medgift-lf-boc-bovw-mnz-IMAGES-cb medGIFT 0,0302   0,001 0,0293 0,0231 0,009
    baseline-sift-early-fusion-cb      medGIFT 0,0016    0   0,0032 0,0038 0,0013
    baseline sift late fusion cb       medGIFT 0,0008    0      0   0,0038 0,0013
    medgift-ef-boc-bovw-reci-IMAGES-cb medGIFT 0,0008 0,0001 0,0007    0   0,0013
    medgift-ef-boc-bovw-mnz-IMAGES-cb medGIFT 0,0007     0      0      0   0,0013
     Table 6. Results of the textual runs for the medical case–based retrieval task.
    Run Name                          Group   MAP GM-MAP bpref P10         P30
    HES-SO-VS FULLTEXT LUCENE         medGIFT 0,169  0,0374 0,1499 0,1885 0,109
    LIG MRIM CB FUSION DIR W TA TB C MRIM     0,1508 0,0322 0,1279 0,1538 0,1167
    LIG MRIM CB FUSION JM07 W TA TB C MRIM    0,1384 0,0288   0,11 0,1615 0,1141
    UESTC case f                      UESTC 0,1288   0,025  0,1092 0,1231 0,0821
    UESTC-case-fm                     UESTC 0,1269 0,0257 0,1117 0,1231 0,0821
    LIG MRIM CB TFIDF W DintQ         MRIM    0,1036 0,0167  0,077 0,0846 0,0705
    nlm-lc-total-sum                  ITI     0,1035 0,0137 0,1053 0,1 0,0628
    nlm-lc-total-max                  ITI     0,1027 0,0125 0,1055 0,0923 0,0538
    nlm-se-sum                        ITI     0,0929  0,013 0,0738 0,0769 0,0667
    nlm-se-max                        ITI     0,0914 0,0128 0,0736 0,0769 0,0667
    nlm-lc-sum                        ITI     0,0909 0,0133 0,0933 0,1231 0,0654
    LIG MRIM CB TA TB JM07 C          MRIM    0,0908 0,0156 0,0799 0,1308 0,0744
    LIG MRIM CB TA TB BM25 C          MRIM    0,0895 0,0143 0,0864 0,1231 0,0654
    LIG MRIM CB TA TB DIR C           MRIM    0,0893 0,0137 0,0804 0,1192 0,0692
    LIG MRIM CB TA TB PIVv2 C         MRIM    0,0865 0,0158 0,0727 0,1192 0,0795
    nlm-lc-max                        ITI      0,084 0,0109 0,0886 0,0923 0,0603
    LIG MRIM CB TA TFIDF C DintQ      MRIM    0,0789  0,014 0,0672 0,0923 0,0692
    nlm-se-frames-sum                 ITI     0,0771 0,0052 0,0693 0,0692 0,0526
    HES-SO-VS CAPTIONS LUCENE         medGIFT 0,0696 0,0028 0,0762 0,0962 0,0615
    LIG MRIM CB TA TB TFIDF C avdl    MRIM    0,0692 0,0127 0,0688 0,0769 0,0692
    nlm-se-frames-max                 ITI     0,0672 0,0031 0,0574 0,0538 0,05
    LIG MRIM CB TA TB TFIDF C         MRIM    0,0646 0,0114 0,0624 0,0692 0,0641
    ibm-case-based                    IBM     0,0484 0,0023 0,0439 0,0577 0,0449
    R1 MIRACL                         MIRACL 0,0421  0,005   0,026 0,0538 0,0462
    R4 MIRACL                         MIRACL 0,0196 0,0008 0,0165 0,0308 0,0282
    R3 MIRACL                         MIRACL 0,012   0,0004 0,0087 0,0192 0,0218
    R6 MIRACL                         MIRACL 0,0111 0,0004 0,0074 0,0192 0,0128
    R5 MIRACL                         MIRACL 0,0024     0   0,0022 0,0038 0,0013
    R2 MIRACL                         MIRACL     0      0   0,0002    0      0




Multimodal Retrieval As in the visual case–based task, only the medGIFT
team [14] submitted multimodal case–based runs. The runs combine the visual
approach based on BoVW and BoC with a Lucene baseline and obtained aver-
aged results when using the combMNZ fusion.


     Table 7. Results of the multimodal runs for the medical case retrieval task.
            Run Name                 Group   MAP GM-MAP bpref P10        P30
            medgift-ef-mixed-mnz-cb medGIFT 0,1017 0,0175 0,0857 0,1115 0,0679
            medgift-ef-mixed-reci-cb medGIFT 0,0514 0,009 0,0395 0,0654 0,0564




4     Conclusions

As in previous years, the largest number of runs submitted for the image–based
retrieval task. However, in 2012 there were 122 runs in this task, eight less than
in 2011. For the case–based retrieval task the number of runs also decreased to
37 (43 in 2011). On the other hand, the number submitted runs at the modality
classification task increased to 43 (34 in 2011).
    There are still different situations as to whether visual, textual or combined
techniques perform better depending on the task. For the modality classification,
a visual run achieved the best accuracy using training data extension. In the case
of the image–based retrieval task, multimodal runs obtained best results. Finally,
for the case–based retrieval task textual runs obtained the best results.
    In 2011, the Xerox team [29] that did not participate in 2012 explored the
expansion of the training set. This approach achieved the best accuracy for
the modality classification task. In 2012, three teams applied expansion of the
training set and also obtained good results. This evolution of techniques is a
good example of the added value of evaluation campaigns such as ImageCLEF
showing the improvements due to specific techniques.
    Many groups explored the same or similar descriptors obtaining often quite
differing results. This shows that particularly the tuning of existing techniques
and the intelligent combination of results fusion can lead to optimal results. Of-
ten, the differences in techniques are quite small and more on intelligent feature
combinations might be necessary to reach conclusive results.


5   Acknowledgements
We would like to thank the EU FP7 projects Khresmoi (257528), PROMISE
(258191) and Chorus+ (249008) for their support as well as the Swiss national
science foundation with the MANY project (number 205321–130046).


References
 1. Müller, H., Clough, P., Deselaers, T., Caputo, B., eds.: ImageCLEF – Experi-
    mental Evaluation in Visual Information Retrieval. Volume 32 of The Springer
    International Series On Information Retrieval. Springer, Berlin Heidelberg (2010)
 2. Clough, P., Müller, H., Sanderson, M.: The CLEF cross–language image retrieval
    track (ImageCLEF) 2004. In Peters, C., Clough, P., Gonzalo, J., Jones, G.J.F.,
    Kluck, M., Magnini, B., eds.: Multilingual Information Access for Text, Speech and
    Images: Result of the fifth CLEF evaluation campaign. Volume 3491 of Lecture
    Notes in Computer Science (LNCS)., Bath, UK, Springer (2005) 597–613
 3. Müller, H., Deselaers, T., Kim, E., Kalpathy-Cramer, J., Deserno, T.M., Clough,
    P., Hersh, W.: Overview of the ImageCLEFmed 2007 medical retrieval and an-
    notation tasks. In: CLEF 2007 Proceedings. Volume 5152 of Lecture Notes in
    Computer Science (LNCS)., Budapest, Hungary, Springer (2008) 473–491
 4. Kalpathy-Cramer, J., Müller, H., Bedrick, S., Eggel, I., Garcı́a Seco de Herrera,
    A., Tsikrika, T.: The CLEF 2011 medical image retrieval and classification tasks.
    In: Working Notes of CLEF 2011 (Cross Language Evaluation Forum). (September
    2011)
 5. Kalpathy-Cramera, J., Hersh, W.: Automatic image modality based classification
    and annotation to improve medical image retrieval. Studies in Health Technology
    and Informatics 129 (2007) 1334–1338
 6. Csurka, G., Clinchant, S., Jacquet, G.: Medical image modality classification and
    retrieval. In: 9th International Workshop on Content-Based Multimedia Indexing,
    IEEE (2011) 193–198
 7. Markonis, D., Holzer, M., Dung, S., Vargas, A., Langs, G., Kriewel, S., Müller, H.:
    A survey on visual information search behavior and requirements of radiologists.
    Methods of Information in Medicine (2012) Forthcoming
 8. Zhang, D., Lu, G.: Review of shape representation and description techniques.
    Pattern Recognition (1) (2004) 1–19
 9. Tirilly, P., Lu, K., Mu, X., Zhao, T., Cao, Y.: On modality classication and its
    use in text–based image retrieval in medical databases. In: Proceedings of the
    9th International Workshop on Content–Based Multimedia Indenxing. CBMi2011
    (2011)
10. Müller, H., Kalpathy-Cramer, J., Demner-Fushman, D., Antani, S.: Creating a
    classification of image types in the medical literature for visual categorization. In:
    SPIE medical imaging. (2012)
11. Tsikrika, T., Müller, H., Kahn Jr., C.E.: Log analysis to understand medical
    professionals’ image searching behaviour. In: Proceedings of the 24th European
    Medical Informatics Conference. MIE2012 (2012)
12. Hersh, W., Müller, H., Kalpathy-Cramer, J., Kim, E., Zhou, X.: The consolidated
    ImageCLEFmed medical image retrieval task test collection. Journal of Digital
    Imaging 22(6) (2009) 648–655
13. Cao, L., Chang, Y.C., Codella, N., Merler, M.: IBM t.j. watson research cen-
    ter, multimedia analytics: Modality classification and case–based retrieval task of
    ImageCLEF2012. In: Working Notes of CLEF 2012. (2012)
14. Garcı́a Seco de Herrera, A., Markonis, D., Eggel, I., Müller, H.: The medGIFT
    group in ImageCLEFmed 2012. In: Working Notes of CLEF 2012. (2012)
15. Collins, J., Okada, K.: A comprative study of similarity measures for content–based
    medical image retrieval. In: Working Notes of CLEF 2012. (2012)
16. Wu, H., Sun, K., Deng, X., Zhang, Y., Che, B.: UESTC at ImageCLEF 2012
    medical tasks. In: Working Notes of CLEF 2012. (2012)
17. Simpson, M.S., You, D., Rahman, M.M., Demmer-Fushman, D., Antani, S.,
    Thoma, G.: ITI’s participation in the ImageCLEF 2012 medical retrieval and
    classification tasks. In: Working Notes of CLEF 2012. (2012)
18. Song, W., Zhang, D., Luo, J.: BUAA AUDR at ImageCLEF 2012 medical retrieval
    task. In: Working Notes of CLEF 2012. (2012)
19. Castellanos, A., Benavent, J., Benavent, X., Garcı́a-Serrano, A.: Using visual con-
    cep features in a multimodal retrieval system for the medical collection at Image-
    CLEF2012. In: Working Notes of CLEF 2012. (2012)
20. Ide, N.C., Loane, R.F., Demner-Fushman, D.: Application of information technol-
    ogy: Essie: A concept–based search engine for structured biomedical text. Journal
    of the American Medical Informatics Association 14(3) (2007) 253–263
21. Vanegas, J.A., Caicedo, J.C., Camargo, J., Ramos, R., González, F.A.: Bioinge-
    nium at ImageCLEF: Textual and visual indexing for medical images. In: Working
    Notes of CLEF 2012. (2012)
22. Vahid, A.H., Alpkocak, A., Hamed, R.G., Caylan, N.M., Ozturkmenoglu, O.:
    DEMIR at ImageCLEFmed 2012: Inter–modality and intra–modality integrated
    combination retrieval. In: Working Notes of CLEF 2012. (2012)
23. Kitanovski, I., Dimitrovski, I., Loskovska, S.: FCSE at ImageCLEF 2012: Eval-
    uating techniques for medical image retrieval. In: Working Notes of CLEF 2012.
    (2012)
24. Stathopoulos, S., Sakiotis, N., Kalamboukis, T.: IPL at CLEF 2012 medical re-
    trieval task. In: Working Notes of CLEF 2012. (2012)
25. Majdoubi, J., Loukil, H., Tmar, M., Gargourri, F.: Medical case–based retrieval
    by using a language model: MIRACL at ImageCLEF 2012. In: Working Notes of
    CLEF 2012. (2012)
26. Gasmi, K., Torjmen-Khemakhem, M., Ben Jemaa, M.: Word indexing versus con-
    ceptual indexing in medical image retrieval (ReDCAD participation at ImageCLEF
    medical image retrieval 2012). In: Working Notes of CLEF 2012. (2012)
27. Crespo, M., Mata, J., Maña, M.J.: LABERINTO at ImageCLEF 2012 medical
    image retrieval tasks. In: Working Notes of CLEF 2012. (2012)
28. Abdulahhad, K., Chevallet, J.P., Berrut, C.: MRIM at ImageCLEF2012. from
    words to concepts: A new couting approach. In: Working Notes of CLEF 2012.
    (2012)
29. Csurka, G., Clinchant, S., Jacquet, G.: XRCE’s participation at medical image
    modality classification and ad–hoc retrieval task of ImageCLEFmed 2011. In:
    Working Notes of CLEF 2011. (2011)